The effects of fasting diets on nonalcoholic fatty liver disease.

This article reviews current evidence on fasting diets as adjunctive therapeutic strategies for nonalcoholic fatty liver disease (NAFLD), the most common liver disease worldwide with no confirmed treatment. Various fasting regimens—including alternate-day fasting, modified alternate-day fasting, intermittent fasting, periodic fasting, time-restricted feeding (TRF), and religious fasting such as Ramadan—are examined for their effects on hepatic steatosis, liver enzymes, fibroblast growth factors 19 and 21 (FGF19/FGF21) signaling, gut microbiota, lipophagy, and metabolic profiles in NAFLD patients. Clinical and experimental studies suggest that fasting diets may reduce liver fat, inflammation, and fibrosis, improve circadian rhythm regulation, modulate metabolic and inflammatory pathways, and promote weight loss with potentially better adherence than conventional calorie restriction. However, the evidence remains limited and heterogeneous, highlighting the need for further well-designed clinical trials to clarify mechanisms, optimize fasting protocols, and compare fasting diets with established dietary patterns in NAFLD management.